Carrera Gauge Swap

[Reebuck1]

I am no expert. In my case I installed a 3.4 996 motor in my 98 Boxster (986).
My 986 (2.5) DME could was not programed run the 3.4 996 motor without a re-flash.
I had two choices:
1) a USA flash that would use the existing secondary air pump and related vacuum tubing. or
2) a ROW (rest of the World) flash that would allow me to remove the secondary
air pump, etc.
I chose the second.
When I was at the Porsche dealer trying to get them to turn on my reciently installed cruse control. They made the comment that the DME was locked.
I assumed that it was done by the individual who did my ROW flash in order to keep the DME from reverting back to the original 2.5 USA flash should the battery be disconnected.. That assumption could have been incorrect.
Can anyone comment???

[Trey T]

What I'm saying is that if the guy locked your DME, I believe he just simply lock it so no one else can touch it. I don't think it has anything to do with "losing the flash" when battery is disconnected.

There's a reason why they call it "flash" because you ONLY "FLASH" ROM not RAM. Another wway of looking at is you don't lose memory from your "flash drive" (aka usb stick) when you remove it from your computer.

For more clarification, I suggest you google ROM (Flash ROM) vs RAM.

[Reebuck1]

Thanks Trey T, I read your suggestion and I think I 've got it.
The solution looks like...change my the cluster coding values for a 996 cluster put into a 986, the order code (EEPROM ?)contained in the vehicle section of the DME needs to be set properly. In my case it would need to be set to the order code for a 996 cab so that the 996 cluster would be recognized and allow recoding. The order code would need to be set to either 996310 - Cabriolet USA or 996311 - Cabriolet RoW

Once this (EEPROM flash chip) is changed in the DME section, an entire scan of all the control modules needs to be carried out and then you will be allowed to enter into the instrument cluster module and change the coding to turn on cruise activate the temp & oil pres. displays. If the model type is still set to 986 or is blank in the vehicle data section, when the scanning of all modules is carried out the cluster won't be recognized as it will be looking for a 986 cluster.

Does that sound correct??

....

[Reebuck1]

If this does not sound correct could someone please speak up !!!!!!!!!!!!
Car back from the Porsche dealer. They did not turn my gauges on. Reason: they were afraid they would possibly disrupt my 996ROW flash.
Further research suggest that this will not happen BUT ......I have to first turn the gauges on in my current gauge cluster. My present gauge cluster (seen below) is a 1998 Boxster gauge cluster that looks like a 996 cluster. It is a boxster cluster because it still has the cars original mother board in the cluster. All that was done was to add all the 996 digital gauges ONLY to my 986 cluster.

Then I need to comparing the data on the flash chip in the 996 mother board with the data on the chip in my 986 cluster(same location on both clusters). The difficulty I am running into is although the chip are in the same location on both mother boards they appear to have different chip numbers. The 996 board shows 93c56B and the 986 board shows sc56M
I can read the chip on the 996 board BUT can not read the chip on 986 board.
Why:: because the chip number does not show in my GQ-4x EPROM Programmer chip listing. Anyone have any ideas??
To help clarify when I installed the 996 motor in the car I ran the extra wire from the 996 oil sending unit to pin #9 blue plug in the back of the gauge cluster to pick up the signal. That was not clear on my note below.
http://i1210.photobucket.com/albums/cc401/jonhoward42/Boxster%20Cruise%20Retrofit/06%20-%20Wiring%20-%20Connecting/6-04-InstrumentClusterConnectorwithVWWireInstalled.jpg


6-04-InstrumentClusterConnectorwithVWWireInstalled.jpg Photo by jonhoward42 | Photobucket
Once I am able to read the code on the 986 chip I can change the code to turn on the two gauges. At that point I can use a PIWIS to turn on the gauges in the cluster and then use the PIWIS to do the same thing and turn the gauges on in the DME.
That means there are two steps to do with the PIWIS.
ALL SHOULD THEN WORK.............Does this sound reasonable???

[Reebuck1]

Ok, here is what I am going to try.

I am going to take the used Mother board I got from the old 996 cluster I bought to make the swap with and re-assemble it with my original 986 analog gauges. Install it in the car and see if the car will run. If it does ( I believe it will) then I will take it to Porsche (to use their PIWIS) to TURN ON my volt and oil pressure gauges even though they will not be in the car. This should allow Porsches PIWIS to sink the 986 DME that thinks it is a 996 ROW DME with the cluster that thinks it is a 996 cluster because it now has the 996 mother board in it. Hopefully I can then bring the car home and put the 986 cluster with the 996 analog gauges in and all should work. I will have to recode the 986 mother board so that the two gauges read OPEN.
If anyone thinks I have lost my mind please let me know. I'll report back once I get it all done.
Keep your feed back coming it has helped a lot !!

[Chuck W.]

Originally Posted by Reebuck1

Ok, here is what I am going to try.....
!

You persistence and determination is admirable. Never give up, never say die..... and keep us posted.

[hemonu]

I do have a PST2 not the newer PIWIS as the dealers have today. It is true, that instrument cluster would nor be found during an automatic scan, but it still would be possible to manually select a 996 cluster, which is installed in a 986 and vice versa. In the coding section for the cluster there are option for OBC and cruise control, but I don't remember options for the voltmeter and oil pressure gauge. I think those are part of the basic firmware of the cluster. So the correct way would be to read the firmware of the 996 board, modify it with your VIN, mileage and car type and then flash it into the 986 board. So you may have to look for another EPROM programmer with can handle the eeprom on your 986 board or you may be stuck.

[Reebuck1]

Hemonu, Thank you very much for the information. Every little bit helps me get closer to solving this problem. It is very much appreciated !!!!!!

[Thumper]

I have installed several Carrera clusters in my '01 Boxster and have never run into the problems you guys seem to be experiencing. The only issue I've ever had was with the top light. I've just ignored it, but thought I would address it if I ever ran across someone with a PST2. As long as you get a cluster from a C2 and follow the instructions on Renntech.org, you should be golden. I installed my first cluster in 2007 and it's working fine to this day.

I am impressed with the talent to work on the circuit boards to replace bad displays, as I would never have the patience or knowledge to do so myself. All of the clusters I have used came from eBay and have only had one that was actually fried. I have only changed them out due to gauge face color and now have a silver faced set from a C2S. The clusters I took out are in other boxsters and all are working fine to this day. Never had a gas gauge issue, but I did have one that took forever to check the oil level. Also never paid more than $200 for a cluster. You just have to be patient and wait for a deal to pop up.

[KevinH1990]

I sent you an e-mail with the file from my cluster attached. My best suggestion is for you to try to upload it to your cluster and see if that works. The process for programming the EPROM chip has worked for several people. You may be correct that your engine swap is preventing it from working for you.

I know this has to be frustrating, so I wish you the best.

Regards,

[Reebuck1]

Kevin, Got the e-mail....Thanks.
This keeps getting more interesting as I go along. Volts and oil P. still do not work but my digital gauges on the 986 mother board are now showing speed in KPH instead of MPH, interesting. The app that runs the attached files is called "Hex Editor Pro" and can be down loaded for free so you can read the files. Sent files to you but can not up load them on this site.

'986 chip' was my original data on the 986 mother board.

'986 chip adj." is the latest update that I have made to the 986 mother board.

"Kevin chip file "is your chip data

"ubsfile996" is the data from the cluster I took the 996 analog gauges from

Do you have any kind of sheet that tells you which bits control which function? or at least which bits control cruise control and top light?

I think I am getting closer but am still some what lost.





Thanks again for all your help. Bob

[KevinH1990]

That's good news. It's always good when perseverance pays off.

I know the feeling - when I saw my voltmeter spring to life I couldn't wait to take a test drive. I had been working on installing the oil pressure sending unit, and I had not reinstalled the sound insulation on the engine covers. Even though it sounded like I was driving in an oil drum with people beating on it with hammers, I couldn't stop smiling.

Right now, I need to replace the oil sending unit in my car. Whenever the ignition is on, it stays the 5 level. According to some posts on Renntech, the sending unit is a part that often fails.

[Benjamin]

I was going to dig out my old EEPROM files this morning but it looks like you got it going.

When I started mine up for the first time after installing the oil sending unit, I thought it wasn't working properly because the meter just pegged at 5 and didn't move. After a few miles it settled down and started working properly. It looks like that's pretty standard, although that's probably not what's happening with Kevin if it had worked before and then stopped.

To isolate the sending unit as the problem, you can unplug the wire to the cluster, and then measure the resistance with an ohm meter between the metal body of the sending unit and the terminal you unplugged the wire from. With the engine off it should read an open circuit (infinite). With the car running and warmed up, it should read roughly between 15 and 90 ohms, depending on RPM. As you rev the engine, the resistance should change. I would probably do that first before spending the $90 on a new unit.

Benjamin

[KevinH1990]

I have my hardtop on right now, so access to the engine compartment is inconvenient. I'll check the connections and the resistance before I shell out $90, but there are numerous threads on Renntech indicating it is a fragile part. Oil Pressure Switch/Gauge not working - 996 Series (Carrera, Carrera 4, Carrera 4S, Targa) - RennTech.org Forums (There isn't much information on this forum because most cars have the stock sending unit that sets off the warning light.)

Normally, the gauge reads 5 bar until the oil warms up and then I'm usually around 3.5 with the car running in the 3000-4000 rpm range.

I was driving at about 70 mph one night when the gauge suddenly went all the way to the top. I thought it might have been a blocked oil passage until I realized that the warning light didn't illuminate. On one of my other cars I would be annoyed. To be honest, I was almost relieved to see that the sending unit is the common cause of this problem. $90 for a sending unit is a lot less than the cost of a new engine.

[Reebuck1]

Took a long test drive today and everything now works !!!
Proof for those that doubt....though for awhile I was in the doubter group:


I never could have done this without every ones help. AGAIN THANKS !!
I made a lot of mistakes along the way and I need to detail them and list them
on this site so others don't have to make the same mistakes. I will be out of pocket until Monday and will take the time to do it then.

Thanks again, Reebuck1

[KRAM36]

Originally Posted by Reebuck1

Took a long test drive today and everything now works !!!
Proof for those that doubt....though for awhile I was in the doubter group:


I never could have done this without every ones help. AGAIN THANKS !!
I made a lot of mistakes along the way and I need to detail them and list them
on this site so others don't have to make the same mistakes. I will be out of pocket until Monday and will take the time to do it then.

Thanks again, Reebuck1

That's awesome! Nice work and persistence too!

This is on my list.

Did you do the 4 Stalk post too?

[Benjamin]

I'm glad you finally got it working! It must feel really good to figure it out. I know how nagging it is for me when I'm working on something like this and something isn't working right. Now that you know how to take the cluster out, changing the bulbs over to the LED color of your choice is an easy mod. Of course then you find yourself wanting to change all of the dash lights over to the new color. I've changed all mine over to blue and love it.

[juncojones]

I'm at the exact same spot, but with a newer generation cluster. It looks GREAT!
Im using the original board form the boxster and the 996 gauges. I've already Transplanted the two flat cable connectors for the new gauges, but no activity at all in that front. I assume they need to be powered on form the cluster itself.

Does anyone knows the two bytes I need to change to enable the Volt and oil pressure gauges? From what I've read, the bytes are different between the 2 type of clusters, but can't find any data for the new generation ones.

Thanks!

[KevinH1990]

The programming for the new style cluster contains many more lines of code than the old style cluster. You can find a DIY that discusses it here: http://www.renntech.org/forums/topic/47801-programming-a-carrera-instrument-cluster-for-transplant-to-a-boxster/ (If you aren't a Renntech member, send me a PM with your e-mail and I'll e-mail the instructions to you.)

I have an old style cluster and have not personally worked with the new style cluster. I think the folks who found success simply copied the entire 996 cluster code into their 986 board and changed the VIN and mileage. The code positions for those data points are known and discussed in the DIY.

Good luck.

[Reebuck1]

I think you will find your answer for code bits on this post

How to - Upgrade to a 996 Instrument Cluster - How To - www.BoXa.net

Go to item #7 on the post and scroll down to where they list code bits to change.
Really great information....easy to understand.

If that does not answer your question let us know here.
Good luck !!